The present invention relates to a method of recording an image utilizing a color-forming reaction between a leuco dye and a developer therefor.
As conventional heat-sensitive transfer mediums, there are known one comprising a combination of a transfer sheet having a thermo-sublimating dye layer on a substrate with a receiving sheet receiving a thermo-sublimating dye image from the back side of said transfer sheet by thermal printing, and one comprising a combination of a transfer sheet having a transfer layer containing a heat fusible substance and a chromatogenous agent (dye or pigment) on a substrate with a receiving sheet.
However, the former heat-sensitive transfer medium using the thermo-sublimating dye is defective in that the dye image formed on the receiving sheet is inferior in preservability and therefore an overcoat must be applied on the transferred image, while the latter heat sensitive transfer medium using the transfer sheet having the transfer layer formed by dispersing dye or pigment in the heat-fusible substance is defective in that when a large amount of the chromatogenous agent is incorporated in the transfer layer in order to obtain high density images, the transfer efficiency deteriorates, and consequently it is difficult to obtain high density images, and further when a large amount of heat fusible substance is used in the transfer layer in order to raise heat-sensitivity, a large amount of heat fusible substance transfers to the receiving sheet side, and consequently when stripping the transfer sheet of the receiving sheet, it is not stripped smoothly and the fine-lined image area becomes indistinct. Moreover, since the transfer sheet contains the chromatogenous agent, it often soils a non-image area when it is brought into a strong contact with the receiving sheet.